Zhang Koukou is tried at Hanzhong Intermediate People's Court in Shaanxi province on Jan 8. [Photo/China Daily] Zhang Koukou had fatally knifed them on eve of Chinese New Year in 2018

Zhang Koukou, who killed three neighbors in revenge for his mother's death, was executed by a court in Hanzhong, Shaanxi province, after China's top court approved his death penalty.

The Hanzhong Intermediate People's Court announced the decision made by the Supreme People's Court to Zhang on Wednesday morning and then executed him under the supervision of prosecutors.

Before the execution, Zhang was permitted by the court to meet his family members.

Zhang, 36, was sentenced to death by the court in Hanzhong on Jan 8 after being convicted of killing Wang Zixin and two of his sons－Wang Zhengjun and Wang Xiaojun－in 2018 and then setting Wang Xiaojun's car on fire with gasoline.

Zhang confessed in the first trial that he committed the offense because of his mother, who had been seriously injured with a stick by Wang Zhengjun during a quarrel in August 1996. She later died from the injuries.

Wang Zhengjun, then 17, was later given a seven-year sentence for intentional injury and was also ordered to pay more than 9,600 yuan ($1,510) in compensation.

"But over the past two decades, I had never given up on the idea of getting revenge for the attack on my mother," Zhang said during the trial.

On Feb 15 last year, the eve of Chinese New Year, Zhang followed Wang Zhengjun and Wang Xiaojun as they made their way home and stabbed them in their necks, bellies and chests several times with a knife. Zhang then broke into Wang's residence, killing the brothers' 70-year-old father, Wang Zixin and setting Wang Xiaojun's car on fire.

The court in Hanzhong said the defendant's actions constituted the crimes of intentional homicide and destruction of property, so it sentenced him to death.

On April 11, the Shaanxi High People's Court upheld the judgment. The death penalty was then submitted to the country's top court for a review under the Chinese Criminal Procedure Law.

After the review, the top court said in a statement issued on Wednesday that the sentence made by the lower courts was based on clear facts and sufficient evidence, and the legal applications in the case and procedures of the hearings were correct and legitimate.

"Zhang's intention and actions were extremely malicious and cruel, as he made a plan before the offense and killed the three on the eve of Chinese New Year, a traditional family reunion day for Chinese people," the statement said.

Chen Weidong, a professor of criminal law at Renmin University of China, said Chinese courts have become more careful about handing down death sentences in recent decades to uphold the protection of human rights, but that does not extend to "those who are extremely ruthless, such as those who kill several people in a case".

In November, for example, two child killers and two serial rapists were executed after the top court approved their death sentences.

Ruan Chuansheng, a law professor at the Shanghai Administration Institute, said the court that first hands down the death sentence is the one that carries it out.